I have been using Calibre pretty much since it was first released, and the original version was not nearly as graceful at handling duplicate ebooks as it is now. As a result, my library of 2000 books has a fair number of dups (the same ebook but in different formats, epub or mobi or whatever).

Is there an easy (I.E. automatic) way to scan the library and merge the duplicates into a single entry? The only way I can see to do it is to manually add the dups again and then delete the superfluous entries. I can do that if I have to but it's tedious.

Oh, and I just now sent another donation for this product. This is the third or fourth time I have donated but I do not care. This software is better designed, maintained, and supported than 99 percent of the so-called 'commercial' software I have purchased. Thanks to the devs for their excellent work!